1. Field of the Disclosure
The present disclosure relates to an acoustics transducer, and in particular relates to a condenser type acoustics transducer.
2. Description of the Related Art
An acoustic transducer can transform a detected sound wave signal into an electronic signal, which is capable of being used in a variety of applications. Acoustic transducers have been widely used in electronic products, such as mobile phones, notebook computers, digital video cameras, microphones, and digital voice recorders. An acoustic transducer typically includes a back plate and a membrane structure, which are disposed opposite to each other. When a sound wave propagates to the membrane structure, the distance between the membrane structure and the back plate is changed due to a pressure change caused by the sound wave. The change of the distance between the membrane structure and the back plate leads to a change of capacitance therebetween. Thus, by detecting the capacitance difference, the detected sound wave signal is transformed into an electronic signal.
However, the effects of residual stress such as compressive stress, tensile stress or gradient stress may be easily existing in the membrane structure. These residual stresses may cause the membrane structure to buckle, tighten or bend. Thus, the acoustic sensitivity of the membrane structure may be reduced, and the membrane structure may be damaged easily. Specifically, the gradient stress may cause a failure of the membrane structure.
Therefore, an acoustics transducer having both a good acoustic sensitivity and a structural reliability is desired.